Apparatus for use by skiers on which they may simulate the motions, exertions and techniques required in skiing has been built and sold for several years. In particular U.S. Pat. No. 3,524,641 was issued to Robert J. Ossenkop on Aug. 18, 1970, for a device comprising a movable carriage on a set of rails. The carriage of that device is constrained in its movement on the rails by flexible members attached to both the carriage and to transverse members between the rails near each end of the set of rails, and a user can move the carriage from side to side on the rails to simulate the Wedeln or “parallel” technique of skiing.
U.S. Pat. No. 3,547,434 was issued to the same inventor on Dec. 15, 1970. This later patent is for a device similar to the first device, but comprising a number of improvements, such as movable footrests on the carriage whereby a user may simulate turning and edging techniques in addition to parallel skiing; and, in some embodiments may also move the feet relative to one another.
The inventions referenced above each include a safety strap attached to a transverse member between the parallel rails and to the carriage on the rails in addition to the flexible member by which the carriage is constrained to travel on the rails. The purpose of the safety strap is to provide for a situation in which the aforementioned flexible member might rupture on one side of the carriage, providing a sudden force urging the carriage to the side where the flexible member remains unruptured, which sudden force could dislodge a user and perhaps cause serious injury. The safety strap in such instance provides a restoring force toward the center tending to lessen the amplitude of carriage displacement that might otherwise occur.
In U.S. Pat. No. 4,743,014, to which this case is related, and by the same inventor, an exerciser is disclosed having a pair of spaced-apart rails, a platform for riding on the rails, a first resilient element providing a first restoring force on the platform, and a second resilient element providing a second restoring force on the platform. The second resilient element has an adjustment element contacting the second resilient element in at least three points.
In the latter exerciser, the rails are held in a spaced-apart relationship by a brace element in the center, which is fastened to the rails by screw-type fasteners, and by transverse elements fastened at the ends of the rails. The transverse elements at the ends are tubular in form, and the rails pass through openings in the tubular transverse elements, fastening to a bracket internal to each tubular transverse element. This joining arrangement is illustrated by FIG. 1A and FIG. 1B of the referenced patent. As shown in these figures rails 301 and 303 pass through holes 305 and 307 respectively into tubular transverse element 309. Inside, the rails are fastened to a bracket 311 by screw fasteners 313 and 315. Rubber-like end caps 317 and 319 close the ends of the tubular transverse element after assembly and act as non-skid pads in contact with the floor in operation. The end caps are of molded rubber-like material, and disk-like pieces carrying designs and lettering are added for identification and aesthetic effect. This particular method of joining and spacing the rails has not proved entirely satisfactory in terms of cost and ease of assembly, and in terms of strength and rigidity of assembly, and the multiple-piece construction of the end caps has also proved to be relatively expensive.
In U.S. patent application Ser. No. 09/533,614, (hereinafter '614), to which the present application is related, a ski-exercising machine is provided comprising a set of at least two parallel rails joined to cross members at the ends, the cross members providing support on a horizontal support surface, and joined to a central frame structure extending from the horizontal surface near the center to the rails, the rails extending from each cross member at each end upward at an acute angle with the horizontal rising to a maximum height in the center; a wheeled carriage riding on the rails; at least one articulated footpad mounted to the wheeled carriage; and a set of three power bands each anchored at both ends by a clamp to a bottom surface of the frame structure beneath the wheeled carriage, passing over separate roller sets, with one or more of the power bands anchored to the wheeled carriage and one or more passing over a roller anchored to the wheeled carriage.
Although related U.S. patents issued to the inventor address the above problem and other problems related to construction and function of various components of the parent ski exerciser, there are still non-obvious improvements desired in several areas related to construction or assembly techniques, profile, materials, operation and longevity of the apparatus. For example, in U.S. Pat. No. 5,147,257 (hereinafter '257), in FIGS. 5A and 5B, a ski exerciser is illustrated both in an elevation view (FIG. 5A), and in a plan view (overhead FIG. 5B). Arcuate rails 15 comprise tubing structures having a continuous arc or bow over their entire length.
Additionally, further non-obvious improvements are desired in several areas related to tension adjustability of the power bands, band roller operation, positioning of individual footpads on the wheeled carriage, simulation of actual skiing movements and dynamics, as well as rehabilitation and versatility of the skiing apparatus to simulate range of motion and balance required in many sports other than downhill skiing. Still further improvements are desired in areas relating to safety aspects of apparatus to minimize the possibility of injury to the user.
It has been discovered partly through empirical methods that an even better action may be simulated with rails shaped somewhat differently than in the prior art. Firstly, the arcuate portions of the parallel rails can be shortened, and the straight portions lengthened to provide more intensity in the simulation of the skiing action. Secondly, the inventor has discovered that further adjustability of the power bands, in addition to footpad positioning, pivoting and sliding action, provide more accurate skiing motion simulation than the apparatus in the referenced prior art.
FIG. 5A in '257 illustrates roller assemblies housing rollers such as rollers 25 and 27 which are identical in size and construction with other illustrated rollers which make rolling contact with resilient members 23 and 59. The diameter of the aforementioned rollers is disclosed as approximately 1 inch, and the rollers are generally cylindrical. It has been discovered that larger rollers, also crowned have a beneficial effect in smoother power band operation. The crowned rollers keep the belts better centered on the rollers.
The present inventor has also determined that improvements may be made in the positioning of wheels for the wheeled carriage, and in the form of the rails and how the wheels interface to the rails.
FIG. 16 in '614 illustrates a ski exercising apparatus 301 according to an embodiment of the present invention having an optional third power band assembled between the first, or outer power band, and the second, or inner, power band, and a pair of tensioning structures (303 and 304), each having a single roller assembly rotatably mounted to the tensioning structure such that consistent tension is provided to the wheeled carriage assembly given a specific range of motion of the carriage assembly.
What is clearly needed is a modularly enhanced ski-excising device that provides further distinct advantages for the expanding field of users. Such an improved device could provide further adjustability of power band tension, and additional pivoting action for suspended footpad assemblies to provide a more realistic simulation of skiing movements and dynamics in varying skiing terrain. What is also clearly needed is an improved method and apparatus enabling the user to quickly interchange footpad assemblies of a wheeled carriage assembly having additional attachments for rehabilitation and selective body strengthening, which simulates the range of motion and balance required in many sports other than downhill skiing, accurately reproducing lateral movements required in most sports, thereby optimizing rehabilitation and helping to prevent injury to the user. Such an improved apparatus incorporates additional safety features, which further protect the user from injury during operation of the exercise apparatus.